Crowned Eagle Is Prob- Ably Satisfactory but It Needs Close Monitoring

194 Accipitridae: vultures, kites, hawks, eagles, buzzards and harriers

rates were in East Coast Littoral, Afromontane Forest and Eastern Zimbabwe Highlands. In the woodland and grassland vegetation types it is restricted to patches of suitable habitat. Movements: The models show it to be sedentary, with little seasonal variation. They show a slight increase in reporting rate in the early part of the breeding season; at this time the eagles are territorial and undertake extensive nuptial displays, possibly resulting in increased conspicu- ousness. Breeding adults are sedentary and juveniles and immatures normally disperse from their natal areas. Breeding: Breeding occurs throughout the range and the models show that the season is mainly August–March, thereby occupying about two-thirds of the 12-month cycle, although breeding activity was recorded at all times of the year. The main egglaying period is August–October, with a peak in September (Irwin 1981; Brown et al. 1982; Tar- boton & Allan 1984; Tarboton et al. 1987b). Historical distribution and conservation: While there has been no major range change in the southern and southeastern parts of the Cape Province, it may have disappeared from the fringes of the Nama Karoo as a result of man’s destruction of ravine forests (Boshoff et al. 1983). Com- mercial plantations have extended its distribution into former grassland areas (Tarboton & Allan 1984). Although numbers may have decreased locally, the current distribution is considered to reflect the historical one closely. The conservation status of the Crowned Eagle is prob- ably satisfactory but it needs close monitoring. Where territories and home ranges in forest and woodland areas abut small-stock farms in the eastern and southeastern Cape Province, it is accused of stock theft and is persecuted by shooting and trapping (Boshoff & Vernon 1980a; Jarvis et al. 1980; pers. obs). In the southern and eastern Cape Province prime habitat has been lost by the clearing of forests for commercial plantations, and the clearance of Crowned Eagle trees in forested ravines (Boshoff et al. 1983; Boshoff Kroonarend 1988). It is more likely to take domestic stock, and there- fore be persecuted, when breeding in plantations away Stephanoaetus coronatus from indigenous forest (Boshoff 1988). Juvenile and imma- ture birds are apparently more prone than adult birds to The Crowned Eagle is an Afrotropical species which is direct persecution by small-stock farmers (Tarboton & restricted to the eastern parts of southern Africa, in South Allan 1984; pers. obs). Africa, Swaziland and Zimbabwe. The most westerly re- A.F. Boshoff cord is from northern Botswana (Aspinwall 1989b). It may be locally frequent or common in patches of prime habitat. It usually occurs singly or in pairs. In prime habitat in the escarpment area of the Transvaal, Recorded in 362 grid cells, 8.0% the distances between breeding pairs are as short as 2–5 km Total number of records: 4345 (Tarboton et al. 1987b). Elsewhere in the Transvaal nests Mean reporting rate for range: 12.0% are 5–12 km apart (Tarboton & Allan 1984). In the eastern Cape Province the mean inter-nest distance is 6 km (range 2–12 km) (Vernon 1984), whereas in the southern Cape Province it is 19.5 km (range 6–32.5 km) (Boshoff 1988). Adult Crowned Eagles are inconspicuous except when Reporting rates for vegetation types undertaking their display flights, which are accompanied % 0816 by a distinctive and far-carrying call. Immatures can be confused with those of the Martial Eagle Polemaetus belli- East Coast Littoral 11.5 cosus. Afromontane Forest 9.1 Habitat: This is essentially a forest eagle but it also occurs E Zimbabwe Highlands 8.7 in dense woodland and forested gorges and ravines in open Valley Bushveld 8.5 savannas and thornveld, and in tall riparian woodland and Sour Grasslands 4.4 gallery forest. It is also found in habitat mosaics compris- Miombo 3.8 ing indigenous forest, exotic plantations, pastures and Moist Woodland 3.4 grasslands. It has adapted to altered environments and nests Mopane 3.2 in alien trees (mainly pines and eucalypts), sometimes in Arid Woodland 2.8 close proximity to human habitation. The highest reporting Mixed Grasslands 2.1 Accipitridae: vultures, kites, hawks, eagles, buzzards and harriers 195

14û

CROWNED EAGLE 5 1 18û

22û 2 6

26û

3 7 30û Reporting rate (%) > 14.3 5.9 — 14.3 2.0 — 5.8

< 2.0 34û 4 8 18û 22û 26û 14û 30û 10û 34û

15 1 5 20 10 10 5

15 2 6 20 10 10 5

15 3 7 20 10 10 5

15 Occurrence reporting rate (%) 4 8 20 Breeding reporting rate (%) 10 10 5

J ASONDJ FMAMJ J ASONDJ FMAMJ Models of seasonality for Zones. Number of records (top to bottom, left to right): Occurrence: 0, 0, 0, 32, 310, 231, 770, 301; Breeding: 0, 0, 0, 12, 65, 96, 111, 73.